This invention relates to an improved fluidized patient support system that is of particular advantage to burn patients, as well as other patients who are immobilized for extended recuperative periods.
Historically, hospital beds for patients have in general been conventional where, though adjustable as to height and attitude a mattress-springs arrangement has been provided for receiving the patient thereon covered, of course, with appropriate bed clothing. Particular problems have developed in use of the conventional hospital beds where the patients, due to prolonged contact with the support surface in generally immobile conditions, have developed decubitus ulcers or bed sores, as a result of pressure points between the support surface and certain portions of the patient's body. Additionally, in the case of burn patients where the severity of the injury or wound is such that the patient is affected over a significant portion of his body, the conventional bed presents problems not only with the healing process due to contact between raw areas of the human body and the support, but also due to fluids exuding from the patient's body. In like fashion, other types of injuries and reasons for confinement have presented problems with the conventional hospital bed.
In order to obviate some of the problems inherent with the conventional hospital bed, fluidized patient support structures have been developed as exemplified in the Hargest et al. U.S. Pat. No. 3,428,973, in which a tank is provided, partially filled with a mass of granular material which is received atop a diffuser surface and is covered with a loose fitting flexible patient contact sheet or surface. Fluid, such as air, is forced through the diffuser surface and fluidizes the granular material, preferably ceramic spheres, with adequate force that a patient received on the flexible sheet is suspended on the fluidized bed. In this fashion, very gentle forces are imparted to the body portions of the patient, whereby the incidence of development of decubitus ulcers is reduced and whereby an individual experiencing trauma, such as produced by severe burns may rest comfortably.
A further fluidized patient support structure is disclosed in the Hargest U.S. Pat. No. 3,866,606 which structure has the same basic elements of that mentioned above with the addition of control means to cyclically fluidize the total mass of granular material, also preferably ceramic spheres, for floatation of the patient, whereby in a non-fluidized state, the patient settles into the mass of granular material which becomes a rigid body contoured structure against which the patient's body may be placed in traction. In like fashion, the cyclic effect of fluidizing-rigidifying the total mass of granular material permits variation in patient attitude, again towards the reduction of the incidence of development of decubitus ulcers. Still further, a similar structure is also shown in the Paul U.S. Pat. No. 4,483,029 in which a variable depth fluidized bed is provided.
In the fluidized patient support systems described above, all of which achieve their intended purpose, the fluidized bed is basically static even when the intermittent fluidization is achieved. In other words, the buoyant forces of the fluidized bed are normally vertical in support of the supine patient. One of the factors influencing the development of decubitus ulcers is the level of flow of blood throughout the patient's subcutaneous capillaries. Coupled with the pressure produced by conventional beds or supports, not only does the patient experience discomfort, but ulcers result.
The improved structure of the present invention will perform at efficacy levels equal to that of the presently commerical fluidized patient support systems. At the same time, structures according to the present invention afford greater patient comfort and improved blood circulation for a patient residing on the support structure. As such, the fluidized patient support structure of the present invention represents an improvement over known prior art structures.